Organization is the key to success. It's better to have a plan going into something then going in blind.
It takes me and my partner a few days to even got to the point where we're coding a mock up. We do research on the client, their industry, their competition, what's going to set them apart, what's going to bring people back to their site, how is their site going to impact their business in a positive way in the long run, how can we speed the process up. All of this comes into play to build a successful website and keep that client working with you on an on going basis.
When you're able to gather this information you already know what they expect to see in their site without them even having to tell you. Of course every company is going to be a little bit different than the others in their industry and that's where they're going to have to fill you in on, but at least you'll know their industry standards on the type of content, keywords, design schemes, stock photos, and all that jazz to look for.
If you don't do this it's like trying to design a bio-nuclear physicist web site. You ever seen one of those? Probably not, so you can't just dive in head first and expect the client to be happy with the first few mock ups you design without knowing symbols and patterns and key points to highlight in the design process.